Two-cycle internal-combustion engine



1,622,717 March 29 1927 R. HILDEBRAND TWO-CYCLE INTERNAL COMBUSTIONENGINE Filed ma# 25. 1925 A fr0/Pnt Y:

Patented Mar. 29, 1927.

UNi'ii-:D STATES mummia, orwiiss'rsn enovns, mssoimr..

TWCLE IITTEBNAL- OOHBUBTION ENGINE.

Appunti@ aiea my as, leas. serial mi. 32,586.

This invention relates generally tointernal combustion engines, andparticularly to a two-cycle internal combustion engine of the loopscavenging type in which scaveng- I ing ports and exhaust (ports arearranged in the wall of the c lin er of said engine 1n proximity to eacother, the main'object of the invention being to produce a two-cycleengine having ports so arranged that the ei- 10. ciency of the engine isincreased.

Prior to this invention engines of the general type of 'the onedisclosed herein and which were provided with scavenging and exhaustports i'n proximity to each other l5 were produced. In one engineheretofore known the exhaust ports were arranged in' a row above a rowof scavenging ports with both rows of cylinder, and in another make ofengine 'the exhaust and scaven ng ports were arranged on opposite sideso the cylinder. There are certain disadvantages in connection with theport arran ents of the engine just referred to, for it is plain in thecase of the engine having the scavenging ports andthe exhaust portsarranged in rows one above the other that the eifective stroke of thepiston would be reduced because of the fact that a comparatively largertion of the'stroke of I0 said pis'ton would required to control therts. In connection with the engine havmg the scaven 'ng and exhaustports in opposite sides o the cylinder said ports were arranged in a rowwhich extended almost 85 entirely around the wh'ole circumference of thecylinder of the engine, and as a result an opportunity was presented forthe scavengin air to short circuit without describing a oop-like paththrough the entire cylinder 40 as desired. Also 'this arrangement of theports made it diflicult to employ a sulicient number of ports.

In theengine disclosed in the present application'the scavenging andexhaust ports are so arranged relative to each other that the port spacein a direction lengthwise of the cylinder is much less than .was the.port space in the engine having scavenging ports and exhaust portsarrangedv one abovethe other, and as a result of this fact theei'ective.

stroke of the piston of the engine is relatively longer. Also, the portarrangement shown herein is such and the ports are lso to follow thedesirable'loop-li rts on the same side of the shaped that thecircumferential `port space is much less than the circumferential portspace of the engine having scavengin and exhaust ports arranged on oposite sides of the cylinder, and consequent y more eicientand completescavenging of the cylinder is obtained. In addition to the foregoing,the arrangement of the ports of my improved engine is such thatscavenging air isv induced e ath throu h the cylinder. p g

With the foregoing and other objects in view, the invention comprisesthe novel construction, combination and arrangement of parts hereinaftermore specifically described and. illustrated in the accompanyingdrawings, wherein Ais shown the preferred embodiment of the invention.However, it is to be understood that the invention comprehends changes,variations and modifications which come within the scope of the claimshereunto appended.

The drawing illustrates a vertical section of the upper portion of anengine made in accordance with my invention.

To illustrate one embodiment of my invention, I have shown in thedrawing a single acting two-cycle engine of the Diesel type, whichcomprises a cylinder C having an inner wall 1 and an outer wall 2 with aspace 3 therebetween through which cooling fluid is caused to circulate.4 designates a cylinder cover by means of v vhichthe upper end of thecylinder is closed, said cover being secured in place on the cylinder bymeans of suitable fastening devices, such as bolts 5, and being providedwith a space 6 through which cooling fluid passes. The cooling Huidenters the space 3 through the inlet passageway at the lower end of thelinder and passes from said space 3 through c t e aperture 8 into theannular s ace 9 atA the upper end of said cylinder. aid cooling fluidthen passes from said -annular space 9 through the passageway 10 intothe space 6 in the cover 4 and om said space 6 through the dischargleconductor 11. It is,

of course, apparent t at a pum will be employed to cause the coolin fiuito circulate as described, but as sai pum part of the present inventionshown the same in the drawing.

P designates the piston of my improved have not forms no engine whichmay be of any desirable type, the particular piston shown in the drawingbeing provided with a piston rod 12 rigidly fixed thereto, which pistonrod is connected in the usual manner to the crank shaft of the engine(not shown).

In the Diesel type of internal combustion engine liquid fuel isintroduced into the combustion chamber ofthe engine in the form of aspray, said injection of fuel taking place after the exhaust ports ofthe engine have been closed and after the air within the cornbustionchamber has been compressed, and because of the hightemperature of thecompressed air combustion 'takes place as soon as the fuel contacts withthe hot compressed air. In the drawing, N designates the nozzle of theengine illustrated there, and by means of which liquid fuel is sprayedinto the combustion chamber of said engine, said nozzle being located atthe upper endI of said combustion chamber and being supported by thecylinder cover 4. o

In the drawing 13 designates the inlet ports of my improved engine whichare lo cated in a horizontal row arranged circumferentially of thecombustion chamber of the engine at a point adjacent to the lower endthereof, said row of ports extending only a portion of the distancearound the combustion chamber and the remainder of the inner wall ofsaid combustion chamber being imperforate. The inlet ports are incommunication with a passageway or passageways 14, which extend throughthe wall of the, cylinder and by means of which air is passed throughsaid ports into the combustion chamber of the engine. In engines of thetype illustrated in the drawing air is forced under pressure through thepassageway or passageways 14 and through the inlet ports 13 into thecombustion chamber, but as the means for introducing said air into thecombustion chamber is well known, I have not shown saine in the drawing.By referring to the drawing it will be seen` that the inlet ports areeach tapering in shape with the smaller portions of said ports at thetop.

15 designates the exhaust ports of the engine which, like the inletports, are in a row arranged circumferentially of the combustion chamberand are extended a portion only of the distance around said combustionchamber. The exhaust ports 15 are in -communication with a passageway orpassageways 16, so that the products of combustion may be dischargedfrom the coinbustion chamber through said ports 15 and passageway 16,said passageway or passageways 16 and said ports 15 preferably (thoughnot necessarily) being inclined downwardly. The exhaust ports are eachtapering inishape, as shown in the drawing, and are arranged with thelarger portions of said ports at 'the tops thereof.

By -referring to the drawing it will be seen that the row of inlet portsand the row -of exhaust ports overlap each other, and also that saidinlet and exhaust ports'alternate with each other. Because of thetapering shapes of said inlet and exhaust ports said ports are capableof being nested, as shown in the drawing, and as a result though quite anumber of comparatively wide ports are employed, the circumferentialport space of the cylinder is not excessive. Also, the overlappingarrangement of the inlet and exhausi"J ports results in a reducedlengthwise of the cylinder where y the effective stroke of the piston isincreased.

When my improved engine is in operation the piston is forced downwardlyby the combustion of the fuel within the piston chamber, and when saidpiston has traveled a sutiicient distance the exhaust ports 15 will beopened. As already stated, the larger portions of the exhaust ports 15are at the top, and because of this fact the products of combustion arequickly discharged from the combustion chamber upon the opening of Saidports. The continued downward movement of the piston P of the engineafter the exhaust ports 15 are opened causes the inlet ports 13 to beopened to admit scavenging air into the combustion chamber. Thescavenging air contacts with the concave top face of the piston P, andsaid scavenging air is deflected thereby, as indicated by the arrows inthe drawing, against the imperforate portion of the inner wall of thecylinder. The air then follows the wall of the cylinder and describesthe loop-like path indicated by'the arrows in the drawing, ressing theburnt gases before it until said air finally escapes from the combustionchamber through the exhaust ports- 15, leaving said combustion chambercomparatively free from burnt gases. On the upward stroke of the pistonthe inlet ports 13 and the exhaust ports 15 are closed, and the airwhich is trapped within the combustion chamber is compressed, at whichtime the liquid fuel is sprayed into the combustion chamber, whereuponthe combustion of the fuel takes place and the pistou is again moveddownwardly. While I have illustrated in' the drawing and described inthe specification a single acting two-cycle engine, it is, of course,apparent that double actin two-cycle engines may be made which em odythe details of my invention.

I claim:

A two-cycle internal combustion engine of the loop scavenging ty ecomprising a cylinder, a piston ada te to reciprocate within saidcylinder, said cylinder having a -pluralit of exhaust ports arranged ina row, 'and a p urality of inlet ports arranged in a row through whichscavenging air is passed into said cylinder, said rows of ports beingort space soarranged that said exhaust ports and saidv extended over aportion only of the circuminlet ports overlap each other, therebyprolference of said cylinder, the side of the cylinviding double row ofports on one side of der wall opposite said double row of ports' 1 saidcylinder in which said exhaust ports being closed to provide thescavenging loops.

5 and sa1d inlet orts alternate with each other- In testimony that Iclaim the foregoing I and saidl doub e row of ports being arran edhereunto ax m si ature. circumferentially of said cylinder and bemg REID HILDEBRAND.

